This invention relates to an apparatus and a method for preventing an inlet vortex. Specifically, this invention relates to an apparatus and method for preventing the formation of a vortex at an inlet of a gas turbine engine while the engine operates on an aircraft located on a tarmac.
Technicians have several options when performing tests with in-service engines. For example, the technician can perform the engine testing on a test stand. Or the technician can perform the engine testing while the engine operates on the aircraft static on the ground. Each testing method has benefits and drawbacks.
Testing an engine in a test stand generally allows for the greatest amount of data acquisition. The test stand can measure the thrust of the engine and includes all of the instrumentation necessary to collect and to interpret engine conditions during operation. The test stand also provides a uniform standard for ensuring that each engine meets all of the flight acceptance requirements established by the certifying authority.
The drawback, however, of a test cell is that the engine must be removed from the aircraft. Removing the engine from the aircraft adds cost and time to the testing procedure.
Testing an engine while the aircraft operates statically on the ground is faster and does not include the expense of engine removal. Such testing does have drawbacks. The main drawback of typical engine installations is the limited power settings available during the test. The technician can only operate typical engine installations at low power settings.
At elevated power settings, operating the engine while the aircraft remains static on the ground can produce vortices between the tarmac and the engine inlet. The vortices can damage the engine by inducing a compressor surge, by creating unstable operating conditions, or by picking up debris.
The present invention increases the range of power settings allowed by the testing of the engine while the aircraft remains static on the ground. Preferably, the present invention expands the range of power settings such that the engine can operate at any power setting while the aircraft remains static on the ground. In other words, the present invention even allows the engine to operate at full power while the aircraft remains static on the ground.